Abstract: A process and a device for bagging a predetermined number of grains with heterogeneous granulometry per sack, particularly seed grains, having a structure for conveying grain by gravity toward means of filling sacks with grain that includes: a collection nozzle for grain arranged on a counter for counting the grain, the counter determining the number of grains n in a sample, a first weighing apparatus for weighing the grain counted, a calculator that takes data related to a number of grains and data related to the mass of that number of grains, and those data make it possible to find a theoretical mass of a predetermined number of grains in a sack, and a second weighing apparatus for weighing the sack, the index value of the second weighing apparatus being the theoretical mass found by the calculator, and when that theoretical mass is measured by the second weighing apparatus, the second weighing apparatus orders the bag filling to stop.